The Maillard Reaction

Abstract

Non-enzymatic catalyzed browning reactions in food and drink are classified into several distinct reaction types including lipid oxidation, caramelization, ascorbic acid oxidation, and the Maillard reaction. The last set of reactions, Maillard, are non-enzyme catalyzed reactions whose product is formed as the result of heat generated during the processing, preparation, and storage of meat, vegetables, fruit, and liquids. These reactions produce both desirable and unwanted results for food preparation. Tea, beer, bread, and syrup are all enhanced by the rich flavor profiles of the Maillard reaction while the organoleptic properties reduce the qualities and appearance of other flavorants and volatiles in foods such as milk. Thus, a complete understanding of the Maillard reaction and its implications in food preparation is very important (Hellwig and Henle, 2014; Bertrand et al., 2018). The Maillard reaction, a condensation of a reducing sugar with amino groups of amino acids, peptides, or protein, is a complex reaction with multiple phases and possible pathways providing a multitude of possible colored and flavored compounds (Figure 14.1). The initial reaction was first observed by Louis-Camille Maillard as he investigated peptide synthesis while heating amino acids in the presence of glycerol and then glucose (Hellwig and Henle, 2014). The key product was a brown precipitate with the concomitant liberation of carbon dioxide. This work led to further investigations into understanding the condensation reactions between amino acids and the carbonyls of reducing sugars (Maillard, 1911, 1916). The first mechanism describing Maillard browning was proposed by Hodge and Rist (1953) with additional modifications suggested by others (Eskin and Shahidi, 2013). While there continues to be an active focus on biomedical applications, where the Maillard reaction is known as glycation producing advanced glycation end products (AGE) with a number of associated pathologies, much of the work in the food industry is concerned with the impact of the reaction on monitor processing, Food Aroma Evolution The Maillard Reaction